Immunonutrition: can you be what you eat?

Abstract

Some nutrients also influence immunologic responses. Those that have been putatively identified as having such properties include glutamine, omega3 fatty acids, arginine, and ribonucleic acid. Use of these immunonutrients in nutrition support has become known as "immunonutrition." Three of these substances (no data for ribonucleic acid) have been evaluated as individual supplements in randomized controlled trials; for the most part, no clinical efficacy was established. Different combinations of these nutrients have been added to standard enteral nutrition support solutions to create several commercial products. Randomized, controlled trials have suggested that recipients of these commercial immunonutrition formulas had better outcomes than controls receiving standard enteral nutrition. However, a number of design and execution problems with many of those trials exist. Furthermore, we do not have sufficient data to determine if the beneficial effects that have been observed result from a pharmacologic effect of the immunonutrient or to the entire nutrition support regimen. Because an immunonutrient can either upregulate or downregulate the immune response, any effect that is seen may be disease state specific.